如果这是一个典型的大西洋夏季，那么您可能在制冷周期的凉爽部分中度过了尽可能多的时间。在我们的气候下，这是一年中这个时候最舒适的地方。将热量从家里移出是一个复杂的过程。在典型的巴尔的摩住宅中，熟悉中央空调实际上融合了房屋中最精致的工程。这可能就是为什么在夏季，它也是最大的能源消费者。当一切正常工作时，制冷周期是化学，力学和技术的奇迹，从房屋中提取热能和湿度，仅留下cool, conditioned comfort。
Willis Carrier didn’t plan it that way. He mistaffght just as well have called his device a “humidity remover” when he invented the first modern air conditioner in 1902 and installed it in a New York City printing factory. He was primarily concerned with lowering humidity inside the building to improve print quality control. To accomplish that, the system he designed utilized the refrigeration cycle principally to extract water vapor from the air. Fortunately for all of us, it also had a pleasant side effect of cooling the air, as well.
Modes of Refrigerant
While Carrier’s patented device was a complicated behemoth that circulated poisonous ammonia as the refrigerant, the basic theory behind the process would sound familiar to anyone learning aboutair conditioningand today. The term “refrigerant” describes any one of a number of chemicals that handle heat in unique, efficient ways, depending on the temperature and pressure at a particular moment:
- 制冷剂在室温下蒸发（或沸腾）。
- 当制冷剂从液体中蒸发到冰冷的蒸发状态时，它很容易吸收热能。
- Refrigerant vapor pressurized to very high temperatures condenses from a hot gas back to a liquid, releasing its load of heat energy.
- When rapidly depressurized, hot liquid refrigerant morphs yet again into a cold vapor and absorbs more heat.
Once you have a single chemical that assumes all those identities, all you need are the mechanics to make it multi-task effectively. A modern air conditioner combines evaporation, air circulation, pressurization and heat transfer into the closed-loop refrigeration cycle that keeps us cool all summer. Here’s a round trip around that circular cycle, starting from cool and winding up there, too.
蒸发器线圈
Installed inside the indoor air handler, the蒸发器线圈incorporates rows of copper tubing that circulate cool refrigerant vapor at low pressure and a temperature of about 40 degrees. The coil also features air passages that allow warm household airflow to pass through the coil by the force of the system blower. Heat energy naturally flows from a hotter zone into a colder zone. Heat in the airflow readily transfers through the highly conductive copper coil surfaces and into the absorbent refrigerant vapor within. With the heat energy extracted, household air leaves the air handler in a cool state and is dispersed by the blower into the ductwork to keep the home comfortable on a hot day.
One more helpful thing happens at the evaporator coil. Exploiting yet another convenient fact of physics, the cold surfaces of the evaporator cause water vapor in warm household air to instantly condense to liquid. This condensate — a busy central A/C can produce over 20 gallons on a humid day — flows into a collection pan and down a drain.
Dry air doesn’t hang on to heat like moist air does, so a dryer indoor environment cools easier and feels more comfortable. That’s why Carrier called his device an “air conditioner” instead of merely a “cooler.” When it comes to有效的室内舒适感，，，，it’s both the heat and the humidity.
压缩机周期
仍然是蒸气，但由于热能的负载而变暖，制冷剂通过绝缘导管流向中央空调的室外一半。它位于位于房屋后面或一侧的橱柜中。机柜内部是一个强大的电压。该组件是您的A/C账单在夏季更高的原因之一；压缩机需要240伏的电力来执行压缩制冷剂流量的重型工作。
由于制冷剂被压缩，热能分子被紧密地挤压在一起，导致制冷剂流动的排放温度飙升至200度以上。在这种过热的高压状态下，制冷剂将压缩机和头部的头部驶出了冷凝器线圈。
The Condensing Process
Think of it as the reverse of the evaporator coil. In fact, the condenser employs a very similar design to circulate refrigerant, as well as allow airflow passage through the coil. Yet it performs an exactly opposite function from the evaporator. As the very hot refrigerant gas enters the condenser coil, it rapidly condenses to a liquid state.
A basic principle of physics states that the condensation process always releases heat energy. Refrigerant does so super efficiently, “rejecting” its load of concentrated heat as it circulates through the coil. This released heat energy is conducted through the copper coil tubes and radiated into the air by coil fins attached to the tubing. The condenser fan located inside the unit pulls air through the coil and disperses that heat into the outdoor air.
如果您曾经站在外面的一半旁边中央空调系统while it’s running, you’ve probably noticed the temperature of air blowing out of the unit. Feel familiar? That heat now exhausting into your backyard used to be inside your house.
回程
离开冷凝器线圈后,制冷剂cycle loops back to the indoor air handler through another insulated pipe. Just before refrigerant re-enters the evaporator, however, one more vital process takes place. In its warm, pressurized liquid state, refrigerant is in no condition to absorb heat inside the evaporator coil. The pressurized refrigerant passes through an expansion valve installed at the evaporator and is forced through a very small orifice. As the refrigerant exits the valve, the instantaneous expansion and rapid pressure drop causes the concentrated molecules of heat energy to spread far apart. The refrigerant temperature plunges and the flow converts to a vaporous state again.
As the closed-loop refrigerant cycle begins anew, the cold refrigerant vapor circulating through the evaporator coil absorbs still another load of heat from your household air, as well as extracting humidity. Meanwhile, you relax in cool comfort and think kind thoughts about Willis Carrier.
Issues With the A/C
所以那样简单吗？实际上，否：以上所有是A/C 101，是（非常）简短版本。对于合格的HVAC技术员来说，制冷周期是一个技术性高度的主题，需要专业的培训和持续研究，以便与利用它的技术的改进保持同步。任何系统都不是万无一失的。制冷周期中的问题可能会对空调的效率和性能。
其中一些常见问题you may encounter include:
- Dirty coil surfaces –The evaporator coil and condenser coil transfer heat efficiently. Not so much, however, if they’re coated with dust and dirt from the airflow passing through the coil. The efficiency of the heat transfer process through the copper coil tubing is severely diminished by dirt and dust accumulations and system performance plunges while operating costs increase.Coil cleaning是标准部分annual A/C maintenance您应该每年安排。
- 制冷剂不足 -因为这是制冷周期的命脉，因此低制冷剂水平可以打开Pandora的系统短缺和神秘的故障。如果您的制冷剂较低，则系统中的某个地方会泄漏，并且仅添加更多的制冷剂，充其量是非常短期的解决方案。一个HVAC service technicianwill measure the refrigerant level. If it’s below specs, he’ll use instruments to track down any leak, then repair it to return the system to full functionality and efficiency.
For more information on the refrigeration cycle as well as professional service to keep it flowing free in your Baltimore, MD home, check out Griffith Energy’sair conditioning solutions，，，，or call 888-474-3391.
